Champion of the Naaru, Hand of A'dal, Legitimate Gladiator titles (DK with Smourne in WoTLK doesn't count for example) and the top50~ guilds who get the first heroic kills before it's either nerfed or gear upgrades come into play (Storm's End had 100 guilds pre-gear upgrades and now there is 700~ or so which makes it pretty common / not prestigious anymore).

Forgot about Scarab Lord, but only those who did it legit. There are people who did it in WoTLK.

Just would like to know the titles people find the most prestigious, for me personally it's Hand of Adal followed by Gladiator(legit ones atleast) also the Insane hardly see that one ever.

I personally wear the Obsidian Slayer title for the realm first sartharion.

I wish they still had the titles for realm first rogue/human though :'( I'd wear that instead.

Insane is a lot more common now since they removed shendrelar and made it easier to get booty bay rep back. It's a cake walk compared to when it first came out. This is one of those title that date is extremely important.

The most prestigious title in game is Scarab Lord without a doubt.

Herald of the titans is still in game and can be gotten rather easily with open raid. It has definitely lost a lot of prestige as well.

According to my armoury, it's the Tranquil Master, but I'd have to say for ANY of my characters, it's the Old PvP title: Grunt (http://eu.battle.net/wow/en/characte...t#81:a468)(yes, only like rank 2, but I would have been a higher rank back then when you could get the old school titles had I pvp'd more)

Most prestigious title of all time? Scarab Lord would be the first one that comes to mind

These are the most prestigous to me because they are either impossible to outlevel, or were hard at the time and unobtainable now:
Scarab Lord
the Celestial Defender
Grand Crusader
The Arena Master
Shado-Master (only title that involves a gold challenge time)
Herald of the Titans (best title I've got)

Current-expansion heroic raid titles are obviously prestigious, but have expiration dates on the prestige. (I really wish they'd all get level and ilvl caps like Herald)

Scarab Lord definitely the most rare and most prestigious of all the titles out there.

But a lot of people who got that title cheated it, as in they transfered to a server that hadn't completed it yet to get it. Also I heard that one server bugged and gave it to everyone that was currently in Silithus when the player completed the quest.

As for my own opinion about prestigious titles, there is none that is prestigious.